Water heater appliances generally operate to heat water within the water heater appliance's tank to a set temperature. Heat pump water heaters are gaining broader acceptance as a more economic and ecologically-friendly alternative to electric and gas water heaters. Heat pump water heaters include a sealed system for heating water to the set temperature. The set temperature is generally selected such that heated water within the tank is at least hot enough for showering, washing hands, etc. Sealed systems generally heat water more efficiently than electric heating elements and gas burners.
A typical sealed system includes a compressor, a condenser, an expansion device and an evaporator operating in a closed loop configuration to manipulate a refrigerant. The condenser may be positioned adjacent to the tank of the water heater such that the refrigerant flowing through may exchange energy with water in the tank of the water heater, heating the water. By contrast, the evaporator of the sealed system may be disposed within a casing such that an airflow may be provided over the evaporator to increase an efficiency of the sealed system.
To assist with providing circulating air over the evaporator, certain sealed systems also include a fan or air handler. The fan draws or forces air over the evaporator in order to facilitate heat transfer between the air and refrigerant within the evaporator and thereby increase the efficiency of the sealed system. However, fans can fail for various reasons, and performance of an associated water heater can suffer without a properly operating fan. Further, identifying a faulty fan, particularly a fan operating at a low RPM, within heat pump water heater appliances can be difficult and/or time consuming.
Accordingly, a method for detecting a faulty air handler of a heat pump appliance would be useful. In particular, a method for detecting a faulty air handler of a heat pump appliance that does not require physical access to the fan would be useful.